Coordinated suppression strategies for passive and active resonances of the MMC‐HVDC AC‐side system on the medium‐ and high‐frequency bands

The medium- and high-frequency resonance between modular multilevel converters (MMCs) the AC grid has attracted increasing attention due to frequent occurrence of events in recent years. Therefore, issues are analyzed, corresponding suppression strategies proposed this paper. First, analytical expression MMC AC-side impedance is established. Then, mechanism influencing factors different types resonances, including active passive resonance, analyzed provide a more comprehensive perspective. To aid these risk indexes defined evaluate risk, then effects compared through calculations. Subsequently, coordinated suitable for situations proposed. key points suppress negative damping at frequency improve integrated system. Finally, verified by simulation results.